Palindrome question 3 difficulty easy

int isspecialchar(char ch)
{
if(ch==’@’)
return 1;
else if(ch==’ ‘)
return 1;
else if(ch==’$’)
return 1;
else
return 0;
}
char tolower(char ch)
{
if(ch>=‘a’ && ch<=‘z’)
return ch;
else if(ch>=‘0’&& ch<=‘9’)
{ ch=ch-‘0’;
return ch;
}
else
{ ch=ch+32;
return ch;}
}
bool checkPalindrome(string s)
{
int s1=0;
int e=s.size()-1;
while(s1<=e)
{
if(isspecialchar(s[s1]))
s1++;
if(isspecialchar(s[e]))
e–;
if((tolower(s[s1]))!=(tolower(s[e])))
return true;
else
{
s1++;
e–;
}

}
return false;
// Write your code here.

}